On December 6, 1917, two tramp steamers, the Mont-Blanc and the Imo, collided in wartime Halifax Harbour, creating what became the largest man-made explosion of its time. More than 2000 people died, 9,000 were injured, 6,000 people were left homeless and an additional 19,000 were left without adequate shelter. In a combination of images and text, a breathtaking account of the magnitude of this event. John Boileau served in the Canadian Army for 37 years, retiring as a colonel in 1999. He is a graduate of the University of New Brunswick and is currently Honourary Colonel of The Halifax Rifles. He is the author of a dozen books of historical non-fiction.